﻿/* 
* Copyright (c) 2009, The University of Texas at Austin
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, 
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, 
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, 
* this list of conditions and the following disclaimer in the documentation and/or other materials 
* provided with the distribution.
*
* Neither the name of The University of Texas at Austin nor the names of its contributors may be 
* used to endorse or promote products derived from this software without specific prior written 
* permission.
* 
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR 
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS 
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
* THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
using System.Text;
using System.IO;

[Serializable]
[Microsoft.SqlServer.Server.SqlUserDefinedAggregate(Format.UserDefined,
    MaxByteSize = 8000)]
public class ConstructSequence : IBinarySerialize
{
    public void Init()
    {
        _sequenceBlob = new StringBuilder();
    }

    public void Accumulate([SqlFacet(MaxSize=-1)]SqlString Value)
    {
        if (!Value.IsNull && Value.Value.Length == 1)
        {
            _sequenceBlob.Append(Value.Value[0]);
        }
    }

    public void Merge(ConstructSequence Group)
    {
        this._sequenceBlob.Append(Group._sequenceBlob);
    }

    [return:SqlFacet(MaxSize=-1)]
    public SqlString Terminate()
    {
        return new SqlString(this._sequenceBlob.ToString());
    }

    public void Read(BinaryReader r)
    {
        _sequenceBlob = new StringBuilder(r.ReadString());
    }

    public void Write(BinaryWriter w)
    {
        w.Write(_sequenceBlob.ToString());
    }

    private StringBuilder _sequenceBlob;
}
